Rotor core



FIG. 1 is a front and top perspective view of a rotor core showing our new design;

FIG. 2 is a front and bottom perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof. 

CLAIM The ornamental design for a rotor core, as shown and described. 